The Pharoah's Faucets
The Pharaoh (curiously advanced for his time period) had a tub over which three faucets were positioned. Faucet A alone could fill the tub in one hour. Faucet B alone could fill the tube in 40 minutes. When Faucets A, B, and C were turned on, the time required to fill the tub was nine minutes less than was required to fill it when only Faucets A and B were on. How much time was required for Faucet C to fill the tub alone?